Pantech Link endless loading screen

Pantech Link endless loading screen

A day ago I was turning the volume on my Pantech Link up and suddenly my screen goes black. I try holding the End Call button (red phone button on some phones) and the keypad lights up but not the screen. So, I take the battery out and wait about 5 minutes, put the battery back in, and hold the End Call button. This time the screen and keypad light up, but when the loading bar on my phone gets full the screen goes black then starts loading again. It repeats this until I have to take the battery out. Has anyone else had this problem? If so, can you explain how to fix it?